I write proc for transfer files through READ_CLIENT_FILE()/WRITE_CLIENT_FILE() and it works from dbisql. When I call it from PB client application it doesn't work for lack of file_transfer_callback().

In SQL Anywhere 12 help I read:

"However, if the client application explicitly creates a temporary stored procedure then the execution of the stored procedure results in the server treating the procedure as having been client initiated. Similarly, if the client application executes a batch statement, then the execution of the batch statement is considered as being done directly by the client application."

In witch way client app can "executes a batch" or "explicitly creates a temporary stored procedure"